xref: /freebsd/sys/security/mac/mac_inet.c (revision d9a42747950146bf03cda7f6e25d219253f8a57a)
1 /*-
2  * Copyright (c) 1999-2002, 2007, 2009, 2019 Robert N. M. Watson
3  * Copyright (c) 2001 Ilmar S. Habibulin
4  * Copyright (c) 2001-2004 Networks Associates Technology, Inc.
5  * Copyright (c) 2006 SPARTA, Inc.
6  * Copyright (c) 2008 Apple Inc.
7  * All rights reserved.
8  *
9  * This software was developed by Robert Watson and Ilmar Habibulin for the
10  * TrustedBSD Project.
11  *
12  * This software was developed for the FreeBSD Project in part by Network
13  * Associates Laboratories, the Security Research Division of Network
14  * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
15  * as part of the DARPA CHATS research program.
16  *
17  * This software was enhanced by SPARTA ISSO under SPAWAR contract
18  * N66001-04-C-6019 ("SEFOS").
19  *
20  * This software was developed at the University of Cambridge Computer
21  * Laboratory with support from a grant from Google, Inc.
22  *
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the above copyright
27  *    notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  *    notice, this list of conditions and the following disclaimer in the
30  *    documentation and/or other materials provided with the distribution.
31  *
32  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
33  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
34  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
36  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
40  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
41  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
42  * SUCH DAMAGE.
43  */
44 
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
47 
48 #include "opt_mac.h"
49 
50 #include <sys/param.h>
51 #include <sys/kernel.h>
52 #include <sys/lock.h>
53 #include <sys/malloc.h>
54 #include <sys/mutex.h>
55 #include <sys/sbuf.h>
56 #include <sys/sdt.h>
57 #include <sys/systm.h>
58 #include <sys/mount.h>
59 #include <sys/file.h>
60 #include <sys/namei.h>
61 #include <sys/protosw.h>
62 #include <sys/socket.h>
63 #include <sys/socketvar.h>
64 #include <sys/sysctl.h>
65 
66 #include <net/if.h>
67 #include <net/if_var.h>
68 
69 #include <netinet/in.h>
70 #include <netinet/in_pcb.h>
71 #include <netinet/ip_var.h>
72 
73 #include <security/mac/mac_framework.h>
74 #include <security/mac/mac_internal.h>
75 #include <security/mac/mac_policy.h>
76 
77 static struct label *
78 mac_inpcb_label_alloc(int flag)
79 {
80 	struct label *label;
81 	int error;
82 
83 	label = mac_labelzone_alloc(flag);
84 	if (label == NULL)
85 		return (NULL);
86 	if (flag & M_WAITOK)
87 		MAC_POLICY_CHECK(inpcb_init_label, label, flag);
88 	else
89 		MAC_POLICY_CHECK_NOSLEEP(inpcb_init_label, label, flag);
90 	if (error) {
91 		MAC_POLICY_PERFORM_NOSLEEP(inpcb_destroy_label, label);
92 		mac_labelzone_free(label);
93 		return (NULL);
94 	}
95 	return (label);
96 }
97 
98 int
99 mac_inpcb_init(struct inpcb *inp, int flag)
100 {
101 
102 	if (mac_labeled & MPC_OBJECT_INPCB) {
103 		inp->inp_label = mac_inpcb_label_alloc(flag);
104 		if (inp->inp_label == NULL)
105 			return (ENOMEM);
106 	} else
107 		inp->inp_label = NULL;
108 	return (0);
109 }
110 
111 static struct label *
112 mac_ipq_label_alloc(int flag)
113 {
114 	struct label *label;
115 	int error;
116 
117 	label = mac_labelzone_alloc(flag);
118 	if (label == NULL)
119 		return (NULL);
120 
121 	if (flag & M_WAITOK)
122 		MAC_POLICY_CHECK(ipq_init_label, label, flag);
123 	else
124 		MAC_POLICY_CHECK_NOSLEEP(ipq_init_label, label, flag);
125 	if (error) {
126 		MAC_POLICY_PERFORM_NOSLEEP(ipq_destroy_label, label);
127 		mac_labelzone_free(label);
128 		return (NULL);
129 	}
130 	return (label);
131 }
132 
133 int
134 mac_ipq_init(struct ipq *q, int flag)
135 {
136 
137 	if (mac_labeled & MPC_OBJECT_IPQ) {
138 		q->ipq_label = mac_ipq_label_alloc(flag);
139 		if (q->ipq_label == NULL)
140 			return (ENOMEM);
141 	} else
142 		q->ipq_label = NULL;
143 	return (0);
144 }
145 
146 static void
147 mac_inpcb_label_free(struct label *label)
148 {
149 
150 	MAC_POLICY_PERFORM_NOSLEEP(inpcb_destroy_label, label);
151 	mac_labelzone_free(label);
152 }
153 
154 void
155 mac_inpcb_destroy(struct inpcb *inp)
156 {
157 
158 	if (inp->inp_label != NULL) {
159 		mac_inpcb_label_free(inp->inp_label);
160 		inp->inp_label = NULL;
161 	}
162 }
163 
164 static void
165 mac_ipq_label_free(struct label *label)
166 {
167 
168 	MAC_POLICY_PERFORM_NOSLEEP(ipq_destroy_label, label);
169 	mac_labelzone_free(label);
170 }
171 
172 void
173 mac_ipq_destroy(struct ipq *q)
174 {
175 
176 	if (q->ipq_label != NULL) {
177 		mac_ipq_label_free(q->ipq_label);
178 		q->ipq_label = NULL;
179 	}
180 }
181 
182 void
183 mac_inpcb_create(struct socket *so, struct inpcb *inp)
184 {
185 
186 	MAC_POLICY_PERFORM_NOSLEEP(inpcb_create, so, so->so_label, inp,
187 	    inp->inp_label);
188 }
189 
190 void
191 mac_ipq_reassemble(struct ipq *q, struct mbuf *m)
192 {
193 	struct label *label;
194 
195 	if (mac_policy_count == 0)
196 		return;
197 
198 	label = mac_mbuf_to_label(m);
199 
200 	MAC_POLICY_PERFORM_NOSLEEP(ipq_reassemble, q, q->ipq_label, m,
201 	    label);
202 }
203 
204 void
205 mac_netinet_fragment(struct mbuf *m, struct mbuf *frag)
206 {
207 	struct label *mlabel, *fraglabel;
208 
209 	if (mac_policy_count == 0)
210 		return;
211 
212 	mlabel = mac_mbuf_to_label(m);
213 	fraglabel = mac_mbuf_to_label(frag);
214 
215 	MAC_POLICY_PERFORM_NOSLEEP(netinet_fragment, m, mlabel, frag,
216 	    fraglabel);
217 }
218 
219 void
220 mac_ipq_create(struct mbuf *m, struct ipq *q)
221 {
222 	struct label *label;
223 
224 	if (mac_policy_count == 0)
225 		return;
226 
227 	label = mac_mbuf_to_label(m);
228 
229 	MAC_POLICY_PERFORM_NOSLEEP(ipq_create, m, label, q, q->ipq_label);
230 }
231 
232 void
233 mac_inpcb_create_mbuf(struct inpcb *inp, struct mbuf *m)
234 {
235 	struct label *mlabel;
236 
237 	INP_LOCK_ASSERT(inp);
238 
239 	if (mac_policy_count == 0)
240 		return;
241 
242 	mlabel = mac_mbuf_to_label(m);
243 
244 	MAC_POLICY_PERFORM_NOSLEEP(inpcb_create_mbuf, inp, inp->inp_label, m,
245 	    mlabel);
246 }
247 
248 int
249 mac_ipq_match(struct mbuf *m, struct ipq *q)
250 {
251 	struct label *label;
252 	int result;
253 
254 	if (mac_policy_count == 0)
255 		return (1);
256 
257 	label = mac_mbuf_to_label(m);
258 
259 	result = 1;
260 	MAC_POLICY_BOOLEAN_NOSLEEP(ipq_match, &&, m, label, q, q->ipq_label);
261 
262 	return (result);
263 }
264 
265 void
266 mac_netinet_arp_send(struct ifnet *ifp, struct mbuf *m)
267 {
268 	struct label *mlabel;
269 	int locked;
270 
271 	if (mac_policy_count == 0)
272 		return;
273 
274 	mlabel = mac_mbuf_to_label(m);
275 
276 	MAC_IFNET_LOCK(ifp, locked);
277 	MAC_POLICY_PERFORM_NOSLEEP(netinet_arp_send, ifp, if_getmaclabel(ifp),
278 	    m, mlabel);
279 	MAC_IFNET_UNLOCK(ifp, locked);
280 }
281 
282 void
283 mac_netinet_icmp_reply(struct mbuf *mrecv, struct mbuf *msend)
284 {
285 	struct label *mrecvlabel, *msendlabel;
286 
287 	if (mac_policy_count == 0)
288 		return;
289 
290 	mrecvlabel = mac_mbuf_to_label(mrecv);
291 	msendlabel = mac_mbuf_to_label(msend);
292 
293 	MAC_POLICY_PERFORM_NOSLEEP(netinet_icmp_reply, mrecv, mrecvlabel,
294 	    msend, msendlabel);
295 }
296 
297 void
298 mac_netinet_icmp_replyinplace(struct mbuf *m)
299 {
300 	struct label *label;
301 
302 	if (mac_policy_count == 0)
303 		return;
304 
305 	label = mac_mbuf_to_label(m);
306 
307 	MAC_POLICY_PERFORM_NOSLEEP(netinet_icmp_replyinplace, m, label);
308 }
309 
310 void
311 mac_netinet_igmp_send(struct ifnet *ifp, struct mbuf *m)
312 {
313 	struct label *mlabel;
314 	int locked;
315 
316 	if (mac_policy_count == 0)
317 		return;
318 
319 	mlabel = mac_mbuf_to_label(m);
320 
321 	MAC_IFNET_LOCK(ifp, locked);
322 	MAC_POLICY_PERFORM_NOSLEEP(netinet_igmp_send, ifp, if_getmaclabel(ifp),
323 	    m, mlabel);
324 	MAC_IFNET_UNLOCK(ifp, locked);
325 }
326 
327 void
328 mac_netinet_tcp_reply(struct mbuf *m)
329 {
330 	struct label *label;
331 
332 	if (mac_policy_count == 0)
333 		return;
334 
335 	label = mac_mbuf_to_label(m);
336 
337 	MAC_POLICY_PERFORM_NOSLEEP(netinet_tcp_reply, m, label);
338 }
339 
340 void
341 mac_ipq_update(struct mbuf *m, struct ipq *q)
342 {
343 	struct label *label;
344 
345 	if (mac_policy_count == 0)
346 		return;
347 
348 	label = mac_mbuf_to_label(m);
349 
350 	MAC_POLICY_PERFORM_NOSLEEP(ipq_update, m, label, q, q->ipq_label);
351 }
352 
353 MAC_CHECK_PROBE_DEFINE2(inpcb_check_deliver, "struct inpcb *",
354     "struct mbuf *");
355 
356 int
357 mac_inpcb_check_deliver(struct inpcb *inp, struct mbuf *m)
358 {
359 	struct label *label;
360 	int error;
361 
362 	M_ASSERTPKTHDR(m);
363 
364 	if (mac_policy_count == 0)
365 		return (0);
366 
367 	label = mac_mbuf_to_label(m);
368 
369 	MAC_POLICY_CHECK_NOSLEEP(inpcb_check_deliver, inp, inp->inp_label, m,
370 	    label);
371 	MAC_CHECK_PROBE2(inpcb_check_deliver, error, inp, m);
372 
373 	return (error);
374 }
375 
376 MAC_CHECK_PROBE_DEFINE2(inpcb_check_visible, "struct ucred *",
377     "struct inpcb *");
378 
379 int
380 mac_inpcb_check_visible(struct ucred *cred, struct inpcb *inp)
381 {
382 	int error;
383 
384 	INP_LOCK_ASSERT(inp);
385 
386 	MAC_POLICY_CHECK_NOSLEEP(inpcb_check_visible, cred, inp,
387 	    inp->inp_label);
388 	MAC_CHECK_PROBE2(inpcb_check_visible, error, cred, inp);
389 
390 	return (error);
391 }
392 
393 void
394 mac_inpcb_sosetlabel(struct socket *so, struct inpcb *inp)
395 {
396 
397 	INP_WLOCK_ASSERT(inp);
398 	SOCK_LOCK_ASSERT(so);
399 
400 	MAC_POLICY_PERFORM_NOSLEEP(inpcb_sosetlabel, so, so->so_label, inp,
401 	    inp->inp_label);
402 }
403 
404 void
405 mac_netinet_firewall_reply(struct mbuf *mrecv, struct mbuf *msend)
406 {
407 	struct label *mrecvlabel, *msendlabel;
408 
409 	M_ASSERTPKTHDR(mrecv);
410 	M_ASSERTPKTHDR(msend);
411 
412 	if (mac_policy_count == 0)
413 		return;
414 
415 	mrecvlabel = mac_mbuf_to_label(mrecv);
416 	msendlabel = mac_mbuf_to_label(msend);
417 
418 	MAC_POLICY_PERFORM_NOSLEEP(netinet_firewall_reply, mrecv, mrecvlabel,
419 	    msend, msendlabel);
420 }
421 
422 void
423 mac_netinet_firewall_send(struct mbuf *m)
424 {
425 	struct label *label;
426 
427 	M_ASSERTPKTHDR(m);
428 
429 	if (mac_policy_count == 0)
430 		return;
431 
432 	label = mac_mbuf_to_label(m);
433 
434 	MAC_POLICY_PERFORM_NOSLEEP(netinet_firewall_send, m, label);
435 }
436 
437 /*
438  * These functions really should be referencing the syncache structure
439  * instead of the label.  However, due to some of the complexities associated
440  * with exposing this syncache structure we operate directly on its label
441  * pointer.  This should be OK since we aren't making any access control
442  * decisions within this code directly, we are merely allocating and copying
443  * label storage so we can properly initialize mbuf labels for any packets
444  * the syncache code might create.
445  */
446 void
447 mac_syncache_destroy(struct label **label)
448 {
449 
450 	if (*label != NULL) {
451 		MAC_POLICY_PERFORM_NOSLEEP(syncache_destroy_label, *label);
452 		mac_labelzone_free(*label);
453 		*label = NULL;
454 	}
455 }
456 
457 int
458 mac_syncache_init(struct label **label)
459 {
460 	int error;
461 
462 	if (mac_labeled & MPC_OBJECT_SYNCACHE) {
463 		*label = mac_labelzone_alloc(M_NOWAIT);
464 		if (*label == NULL)
465 			return (ENOMEM);
466 		/*
467 		 * Since we are holding the inpcb locks the policy can not
468 		 * allocate policy specific label storage using M_WAITOK.  So
469 		 * we need to do a MAC_CHECK instead of the typical
470 		 * MAC_PERFORM so we can propagate allocation failures back
471 		 * to the syncache code.
472 		 */
473 		MAC_POLICY_CHECK_NOSLEEP(syncache_init_label, *label,
474 		    M_NOWAIT);
475 		if (error) {
476 			MAC_POLICY_PERFORM_NOSLEEP(syncache_destroy_label,
477 			    *label);
478 			mac_labelzone_free(*label);
479 		}
480 		return (error);
481 	} else
482 		*label = NULL;
483 	return (0);
484 }
485 
486 void
487 mac_syncache_create(struct label *label, struct inpcb *inp)
488 {
489 
490 	INP_LOCK_ASSERT(inp);
491 
492 	MAC_POLICY_PERFORM_NOSLEEP(syncache_create, label, inp);
493 }
494 
495 void
496 mac_syncache_create_mbuf(struct label *sc_label, struct mbuf *m)
497 {
498 	struct label *mlabel;
499 
500 	M_ASSERTPKTHDR(m);
501 
502 	if (mac_policy_count == 0)
503 		return;
504 
505 	mlabel = mac_mbuf_to_label(m);
506 
507 	MAC_POLICY_PERFORM_NOSLEEP(syncache_create_mbuf, sc_label, m,
508 	    mlabel);
509 }
510